1. Field of the Invention
The present invention is related to a communication device and a method used in a wireless communication system, and more particularly, to a communication device and a method of handling parameter configurations in a wireless communication system.
2. Description of the Prior Art
A long-term evolution (LTE) system supporting the 3rd Generation Partnership Project (3GPP) Rel-8 standard and/or the 3GPP Rel-9 standard are developed by the 3GPP as a successor of the universal mobile telecommunication system (UMTS) for further enhancing performance of the UMTS to satisfy increasing needs of users. The LTE system includes a new radio interface and a new radio network architecture that provides high data rate, low latency, packet optimization, and improved system capacity and coverage. In the LTE system, a radio access network known as an evolved universal terrestrial radio access network (E-UTRAN) includes multiple evolved Node-Bs (eNBs) for communicating with multiple user equipments (UEs), and for communicating with a core network including a mobility management entity (MME), a serving gateway, etc., for Non-Access Stratum (NAS) control.
A LTE-advanced (LTE-A) system, as its name implies, is an evolution of the LTE system. The LTE-A system targets faster switching between power states, improves performance at the coverage edge of an eNB, and includes advanced techniques, such as carrier aggregation (CA), coordinated multipoint (CoMP) transmissions/reception, uplink (UL) multiple-input multiple-output (UL-MIMO), etc. For a UE and an eNB to communicate with each other in the LTE-A system, the UE and the eNB must support standards developed for the LTE-A system, such as the 3GPP Rel-10 standard or later versions.
An eNB may simultaneously communicate with multiple UEs (e.g., co-scheduled UEs) via the same resource to improve throughput of the system. However, interference may occur to communications between the eNB and the UEs, when the UEs share the same resource. Thus, the eNB may schedule the UEs to use various parameter configurations, to mitigate the effect of the interference. However, the number of the parameter configurations may be large, and this causes large overhead for transmitting information of the parameter configurations. The benefit of the resource sharing (e.g., multi-user MIMO (MU-MIMO)) is reduced due to the overhead.
Hence, how to conveying information of the parameter configurations efficiently is an important topic to be discussed.